The government exists almost solely for the formation of a collective defense, originally what would become "police" and their equivalents was the mechanism, a core of trained professionals a new army could be formed around thanks to the 2nd amendment. At least that's what I got reading the federalist papers. We didn't even decide to fully create a real standing military until pirates were enslaving our ships, the only remnants was a mostly ceremonial/emergency 2 or 3 regiments.